docs: def addSourceGroup(self, sourceGroupUri, weight):
          """
          add a list of relevant sources by specifying a whole source group to the topic page
          @param sourceGroupUri: uri of the source group to add
          @param weight: importance of the provided list of sources (typically in range 1 - 50)
          """
          assert isinstance(weight, (float, int)), "weight value has to be a positive or negative integer"
          self.topicPage["sourceGroups"].append({"uri": sourceGroupUri, "wgt": weight})